Investor Learning Center

4C’s : Diamond Color

The evaluation of color can be viewed in two primary categories.

1. The Evaluation of White Diamonds

As a perfectly formed diamond has no color, the lack of hue represents a better quality diamond. When grading a diamond’s color the stone is compared against a set of 23 master stones each of which displaying a varying amount of color. As the most common imperfection is caused by a diamond being exposed to low levels of nitrogen resulting in a yellowish hue, each master stone displays a slightly more saturated yellowish hue. These stones are represented by a 23 letter scale. D being colorless, and Z displaying a light yellow hue. This scale is further simplified into the following categories.

Colorless (D-F)

Near Colorless (G-J)

Faint (K-M)

Very Light (N-R)

Light (S-Z)

2. The Evaluation of Rare Colored Diamonds

While imperfections in the formation of a diamond due to exposure to nitrogen are common, exposure to high levels of nitrogen, other elements, irradiation, or plastic deformation is extremely rare. It just so happens these other more rare deformations can manifest as a brighter, more saturated color in a diamond. Due to their rarity and beauty these stones can fetch much higher prices at market. Similar to the evaluation of white diamonds, a colored diamond is evaluated based on the color. However because color can be expressed in such a wide variety, the process of evaluation is much more rigorous. For rare colored diamonds the GIA evaluates a stone’s color alone based on the same 3 principles.

Hue :

The hue is the primary color the diamond exhibits. The GIA has broken this down into 27 possible categories, as well as 2 color modifiers (Brown & Grey). Depending on the diamond’s color it can be said to be composed of 2 colors. For example a purplish pink diamond is composed of both purple and pink. When a multiple color value is given to a diamond it will display more of the last color than the first. It should also be noted that pink diamonds have their own individual scale.

The first 27 Hues are as follows

1. Yellow

2. Greenish Yellow

3. Green Yellow

4. Yellow Green

5. Yellowish Green

6. Green

7. Bluish Green

8. Blue Green

9. Green

10. Greenish Blue

11. Blue

12. Violetish Blue

13. Bluish Violete

14. Violete

15. Purple

16. Reddish Purple

17. Red Purple

18. Purple Red

19. Purplish Red

20. Red

21. Orangy Red

22. Reddish Orange

23. Orange

24. Yellowish Orange

25. Yellow Orange

26. Orange Yellow

27. Orangy Yellow

Including The Pink Scale adds the following 4 values.

1. Purplish Pink

2. Purple Pink

3. Pink

4. Pink Rose

5. Pink Champagne

These values along with the two modifiers (Brown & Grey) amount to 128 possible classifications for Hue alone.

Tonality :

Each rare colored diamonds color is graded based on it’s tone, or color intensity. The lighter or darker the color or hue of the diamond is, the more or less valuable it is.

Grading tone involves the following seven factors:

1. Very Dark

2. Dark

3. Medium Dark

4. Medium

5. Medium Light

6. Light

7. Very Light

Saturation :

Each rare colored diamonds color is graded based on a saturation of color consisting of 6 possible categories.